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Indexed by:期刊论文

Date of Publication:2012-06-01

Journal:MATERIALS SCIENCE-POLAND

Included Journals:SCIE、EI

Volume:30

Issue:2

Page Number:151-157

ISSN No.:2083-1331

Key Words:vanadium dioxide; ammonium metavanadate; phase transition; microstructure; pyrogenation

Abstract:A facile process was developed for synthesizing vanadium dioxide (VO2) by pyrolyzing ammonium metavanadate (NH4VO3) in nitrogen flow. The process was designed on the base of thermodynamic modeling of chemical reaction and thermal analyzing of NH4VO3 pyrogenation in N-2 gas, and optimized by experiments. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were applied to characterizing the product VO2. Thermo-gravimetric analysis (TG) and DSC were used for analyzing the process of NH4VO3 pyrogenation. The experimental results indicated that VO2 microcrystal particles were successfully synthesized. The product VO2 presents two kinds of micro morphologies, torispherical and pentagonal prism. The phase transition mainly takes place at 338.4 K and 341.9 K. The average enthalpy of the phase transition is 28.82 J/g.